1. Field of the Invention
The invention relates to a torsional vibration damper.
2. Description of the Related Art
A torsional vibration damper of the aforementioned type is known, for example, from DE German reference 34 11 092 C2, and has a drive-side transmission element and an output-side transmission element rotatable relative thereto. The output-side transmission element, according to FIG. 4 of the reference, is centered relative to the drive-side transmission element via a radial slide bearing and can be held at a predeterminable axial distance from the drive-side transmission element by means of an axial slide bearing. The axial slide bearing is arranged radially inside the radial slide bearing; specifically, so as to be located axially between a central journal embodied on the output-side transmission element and the crank shaft of a drive.
FIG. 3 of the aforementioned reference shows a similar torsional vibration damper, but with a roller bearing. This torsional vibration damper is embodied on its output-side transmission element with indentations, which are aligned with attachment means for attaching the drive-side transmission element to the crank shaft. Indentations of this type are intended to allow a pre-assembled torsional vibration damper to be attached to the crank shaft, after the insertion of the attachment means, by means of the aforementioned indentations. However, it is disadvantageous in indentations of this type that wear particles stemming from the friction clutch (shown in FIG. 1), and especially from the friction linings, can penetrate through the indentations into the region between the two transmission elements and thus enter the extension area of the bearing. In the case of roller bearings, this is not necessarily a great misfortune, especially when the roller bearing, as shown in FIG. 3, is capped on the side facing the recess. However, in the case of radial slide bearings, contamination with wear of this sort can lead to destruction. It is presumably for this reason that in the embodiment with the radial slide bearing in FIG. 4 of the aforementioned reference, no indentation is provided for the passage of attachment means, even though the radial slide bearing has a seal. If the aforementioned indentations for the attachment means are omitted, however, the mounting of the torsional vibration damper on a crank shaft becomes problematic. Furthermore, an added seal increases the cost of construction and reduces durability, because it behaves as a wear component. Damage to the seal can lead to destruction of the radial slide bearing due to penetrating solid particles. For these reasons, the space and cost advantages attained by the use of slide bearings are at least partially nullified.